1. Field of the Invention
This invention relates to the field of computer graphics systems. More particularly, this invention relates to generation of high resolution stereo 3D images in a head tracked stereo display system.
2. Art Background
The human eye can be modeled as an optical system coupled to a retina, with the retina functioning as a light transducer. The human eye is immersed in physical space filled with light rays. A point source of light exists at every point in the physical space that is a boundary between transparent and opaque surfaces, or a boundary between transparent surfaces of different refractive indices. Human stereo vision is achieved by immersing the two eyes at different locations within the physical space.
A head tracked stereo display system simulates the interaction of human eyes with the light rays of the physical space in order to enable a viewer to perceive 3D images. A head tracked stereo display system senses the location in physical space of the viewer's head and eyes, computes a pair of stereo images of a virtual object based upon the location of the head and eyes, and generates the stereo image on a stereo display device.
A head tracked stereo display system requires that only two images be computed and generated at a time, which results in substantially less computation than holographic systems. Moreover, the pair of stereo images have the same appearance as a hologram. With a head tracked stereo display system, the virtual object appears to remain stationary when the viewer's head tilts, or when the viewer's head moves to look around the side or over the top of the virtual object. For further discussion regarding head tracked stereo display systems, refer to Paley, W.B. Head-tracking Stereo Display, Techniques and Applications, Proceedings of SPIE, February 1992.
However, the range of head movement available to the viewer in previous head tracked stereo display systems is limited because the stereo display device remains stationary as the viewer's head moves. As the viewer's head moves around to the side of the virtual image rendered on the stereo display device, the virtual image becomes clipped due to the angled position of the viewer's head in relation to the display surface of the stereo display device.
Moreover, previous head tracked stereo display systems cannot intermix light from the virtual objects and light reflected from real objects in order to enable a viewer to perceive a natural arrangement for the real and virtual objects. If the viewer perceives the stereo images while facing the stereo display device, physical objects positioned between the stereo display device and the viewer's head block the light from the stereo display device and interrupt the virtual image.
As will be described, the present head tracked stereo display system generates complex 3D stereo images to enable a greater range of head movement for a viewer. Moreover, the present head tracked stereo display system intermixes light virtual and real objects to enable a viewer to perceive a natural arrangement for the real and virtual objects.